Process for making combination yarn and product



United States Patent Claims ABSTRACT OF THE DISCLOSURE Process for making elastic yarn, and novel yarn obtained thereby, wherein a crimped synthetic multifilament yarn component, the filaments of which have a titer greater than six denier, is ply-twisted with another crimped synthetic multifilament yarn component This invention relates to a process for making combina tion yarn and the novel yarn obtained thereby, and more particularly, it relates to a process for making an elastic combination yarn and to a yarn having good elastic extension.

It is known that elastic crimped yarn can be made by the temporary high-twisting of synthetic multifilament yarns and heat-setting the yarns while they are temporarily highly twisted. Attempts have also been made to manufacture yarns having a high elastic extension by the aforesaid temporary high-twisting and heat-setting. A yarn with a high elastic extension is one which resist any elongation or tensile stress and resumes its original shape and length as quickly and as completely as possible after the stress has been relaxed.

In prior attempts to produce yarns with high elastic extension, multifilament yarns having individual filaments of three denier have been subjected to temporary hightwisting by means of a false-twist apparatus and heatset in the highly twisted state at temperatures relatively close to the fusion point of the material. Thereafter, two yarns which have been high-twisted in opposite directions are ply-twisted with a relatively large twist in the order of 200400 turns per meter. These yarns, however, have had only limited elastic extension.

Attempts have been made to use yarn components containing individual filaments with higher titers to permit greater elastic extensions. These materials have been unsatisfactory for most textile uses because their hand is too rough.

This invention provides a process for the production of highly elastic yarn which has a desirable hand. This invention also provides a highly elastic yarn having a desirable hand.

Further and more specific objects, features, and advantages will clearly appear from the detailed description given below.

The invention comprises the novel products as well as the novel processes and steps of processes according to which such products are manufactured, the specific embodiments of which are hereinafter described by way of example and in acordance with which it is presently preferred to practice the invention.

Briefly, the process of this invention comprises temporary high-twisting a synthetic multifilament yarn having filaments with a titer above about six denier, heatsetting the highly twisted yarn so that a highly elastic component is obtained, and ply-twisting the highly elastic heat-set yarn with a second yarn. The product of this invention is a highly elastic yarn which comprises a tem- 3,420,049 Patented Jan. 7, 1969 porarily highly-twisted and heat-set multifilament yarn, the individual filaments of which are at least about six denier, ply-twisted with at least one additional yarn. The additional yarn with which the multifilament yarn is plytwisted can be the same or a different synthetic crimped multifilament yarn and or a wrapping of natural or artificial staple fibers.

The combination yarn produced by combining a crimped synthetic multifilament yarn made from very coarse individual filaments with other yarn components according to this invention is found to have an agreeable soft hand together with a higher elastic extension than has heretofore been possible. The yarn of this invention is excellent for the manufacture of elastic knitwear and woven goods, and such yarn is especially useful for the production of sportswear such as ski trousers, swimwear, and the like. These yarns can be used in finished goods in lieu of elastomer-synthetic stretch yarns.

It will be understood herein that the temporary hightwisting and heat-setting in the high-twisted state of the highly elastic component is the technique known as falsetwisting. In this technique the synthetic yarn is given a temporary high twist of the order of thousands of turns per meter and, while in such highly twisted configuration, is heated to a temperature somewhat below its fusion point of the synthetic material. The yarn is then cooled to temperatures substantially below the fusion point so as to permanently fix the twist in the yarn, and the twist is released to provide a highly elastic yarn.

As set forth above, the multifilament highly elastic component is made from a synthetic yarn having filaments with a titer above about six denier. In carrying out this invention it is preferred that the highly elastic component have a total titer of from about 50 to about 200 denier. It is further preferred that the titer of the individual filaments range from about 10 to about 20 denier.

The highly elastic component can be made from a wide variety of synthetic multifilament yarns. The yarns are desirably those having a relatively sharp softening or melting point. Thus, the synthetic multifilament yarns of this invention can comprise polyester fibers such as polyethyleneglycol-terephthalate and the like or polyolefins such as polypropylene and the like. It is especially preferred to use multifilament yarns comprising polyamides, such as polyhexamethyleneadipamide (nylon 66), condensation products of e-aminocaproic acid (nylon 6) or ll-amino-undecanoic acid (nylon 11), and the like.

As mentioned above, the other yarn components can be multifilament synthetic yarn, a temporarily highlytwisted and heat-set multifilament synthetic yarn, a staple fiber-wrapped multifilament or temporarily highly twisted and heat-set multifilament synthetic yarn, or a yarn comprised of staple fibers.

In one aspect of this invention the highly elastic component is wrapped with staple fibers prior to ply-twisting with a second crimped multifilament yarn which has also been wrapped with staple fibers. In another preferred embodiment of this invention, the highly elastic component is wrapped with an elastic false-twisted crimped multifilament synthetic yarn, the individual filaments of which have a titer of from about 2 to about 3.5 denier. If desired, this second low-denier multifilament yarn can be wrapped with staple fibers.

The synthetic multifilament yarn used in conjunction with the highly elastic component of this invention preferably comprises the same materials as set forth above for the highly elastic component, but it will be understood that the synthetic material used in the other component can be the same as or different from the synthetic material used in the highly elastic component. The staple fibers used in the practice of this invention can be natural 3 fibers of animal or vegetable origin such as wool, cotton, and the like, artificial fibers such as those prepared from viscose rayon and the like, or synthetic materials such as polyacrylonitrile and the like.

The yarns of this invention possess a high elastic extension. Generally, such yarns have an elastic extension of the order of about 25% and above, and frequently of the order of about 30% and above.

The elastic extension as used herein is determined according to the following procedure: Five strands of eight turns of yarn each one meter long, are unwound from cross bobbins on which the yarn is maintained in the tensioned condition. The unwinding is conducted under suflicient tension (about 0.1 g./ denier) so that the yarn is stretched straight. The strands are then immersed for 30 seconds in 60 C. water containing a small quantity of a wetting agent.

The wetted strands are suspended from a hook and weighted while in the wet condition to maintain a stress of about 0.2 g./denier, so that the suspended strands are completely smooth. After remaining under this tension for one minute, the lengths of the five strands (X to X are measured. The weights are then removed and the strands are dried While hanging freely suspended without any weights at 5060 C. When the strands are dry they are weighted to maintain a stress of 0.02 g./dcnier, and after one minute their weighted lengths (Y to Y are measured.

The elastic extension is then calculated according to the following equation:

Elastic Extension 100 X 100 where The following examples are given to illustrate preferred embodiments of the invention as it is now preferred to practice it. It will be understood that these examples are illustrative, and the invention is not to be considered as restricted thereto except as indicated in the appended claims.

Example I A polyhexamethylene-adipamide (nylon 66) 60-denier multifilament yarn consisting of four individual -denier filaments is temporarily high-twisted on a false-twist device at 3100 turns per meter in the z direction and heated in the highly twisted state at 235 C. for one second. Two 70-denier nylon 66 multifilament yarns each consisting of 23 individual filaments having a titer of about 3.03 denier are temporarily high-twisted at 3000 turns per meter in the s direction by means of a false-twisting device and heated at 235 C. for 0.5 second in the high-twisted state.

The crimped 60-denier multifialment yarn is then first ply-twisted at 300 turns per meter in the z direction with one of the crimped 70-denier multifilament yarns. The resulting ply yarn is then ply-twisted with the other crimped 70-denier multifilament yarn at 100 turns per meter in the s direction.

The combination yarn so obtained according to this invention exhibits an elastic extension of 31.4%.

For comparison purposes, a 70-denier nylon 66 multifilament yarn consisting of 17 individual filaments having a titer of about 4.10 denier with a spinning twist of approximately turns per meter is temporarily high-twisted at 3000 turns per meter by means of a false-twisting device and heated at 230 C. for one second in the high-twisted state. A second yarn having the same composition is treated in the same Way, but temporarily high-twisted in the opposite direction and the two yarns are ply-twisted at 300 turns per meter in the s direction.

This comparison plied yarn not made in accordance with this invention exhibits an elastic extension of 21.2%.

Example II A -denier nylon 66 multifilament yarn consisting of 5 individual filaments having a titer of 15 denier is temporarily high-twisted at 3100 turns per meter in the s direction by means of a false-twisting device and heated at 235 C. for approximately one second inthe highly twisted state. A 20-denier nylon 66 multifilament yarn consisting of seven filaments having a titer of about 2.86 denier is temporarily high-twisted at 5100 turns per meter in the z direction by false-twisting and heated to 220 C. in the highly twisted state for approximately 0.5 second.

The crimped 75-denier polyamide multifilament yarn is then wrapped on a ring-spinning machine with a cotton roving having a metric number of 6.0 at an extension rate of approximately 19. In the same operation the wrapped 75-denier yarn is ply-twisted with the crimped 20-denier yarn, according to the process described in U.S. patent application S.N. 289.475.

The total twist used in Wrapping and ply-twisting the yarn is 700 turns per meter in the s direction. The finished yarn consists approximately of 50% cotton and 50% polyaminde threads. It exhibits a high elastic extension and good slip proofness of the cotton fibers, that is, the cotton fibers elongate and contract with the highly elastic component and are not stripped 01f the yarn.

Example III A 75-denier polyethyleneglycol-terephthalate multifilament yarn consisting of five filaments having a titer of 15-denier is temporarily high-twisted on a false-twist machine at 3100 turns per meter in the s direction and heated at 235 C. for approximately one second in the highly twisted state.

A 25-denier multifilament yarn consisting of the same polyester and being comprised of eight individual filaments having a titer of about 3.12 is temporarily high-twisted in the z direction at 5100 turns per meter and heated at 235 C. for approximately 0.5 second. The crimped 75-denier polyester yarn is then wrapped with a wool roving having a metric number of 5.6 on a ring-spinning machine with an extension of approximately 20. In the same operation the wrapped polyester yarn is ply-twisted with the crimped ZO-denier polyamide yarn according to the process described in Example II. The total twist used in the wrapping and ply-twisting is 520 turns per meter in the s direction.

The yarn consists approximately of 50% Wool and approximately 50% synthetic fibers. It exhibits high elastic extension and good slip proofness of the wool fibers.

Example IV In this embodiment of the invention a 60-denier multifilament yarn consisting of the condensation product of e-aminocaproic acid (nylon 6) and comprised of four filaments having a titer of l5-denier is used. The multifilament yarn is temporarily high-twisted on the false-twist device at 3100 turns per meter in the z direction and heated to C. for one second in the highly twisted state. A lSO-denier nylon 6 multifilament yarn consisting of 46 filaments having a titer of 3.25 denier is tempo rarily high-twisted at 2200 turns per meter in the s direction by false-t wisting and heated at 195 C. for approximately one second in the high-twisted state.

The crimped 60-denier multifilament yarn is then plytwisted with the crimped ISO-denier multifilament yarn on a ring twisting machine at 300 turns per meter in the z direction. The combination yarn so obtained exhibits high elastic extension.

Example V As a variation of Example II, the 75-denier nylon 66 crimped multifilament yarn of that example is wrapped on a ring spinning machine with a polyacrylonitrile stapl fiber roving having a metric number of 2.3 at an extension of about 20. In the same operation the wrapped yarn is plied with the 20-denier nylon 66 'multifilament yalr of Example H.

The total twist used in the wrapping and plying is 56 turns per meter in the s direction. The yarn contains ap proximately 67% polyacrylonitrile staple fiber and ap proximately 33% of polyatmide. The combination yarn so obtained shows a high elastic extension.

Example VI Two 60-denier nylon 66 multifilaments yarns consisting of four individual filaments having a titer of 15-denier are crimped according to the process utilized on the 60- denier multifilament yarn of Example I. Each of these multifilmment crimped yarns is then wrapped with a viscose roving having a metric number of 5 on a ringspinning machine at an extension rate of approximately 20.

The two wrapped yarns are then plied at 500 turns per meter. The combination yarn has high elastic extension and good slip proofness of the stable fibers.

Example VII Two 60-denier polypropylene multifilarnent yarns, one of which consists of three individual filaments having a titer of 20-denier each and the other of which consists of 20 individual filaments having a titer of 3-denier each are individually temporarily high-twisted at 3200 turns per meter by means of a false-twisting device and heated at 145 C. in the high-twisted state for one second.

Both yarns are subsequently ply-twisted on a stagetwisting machine by means of a hollow spindle. A combination yarn with a very high elastic extension is obtained.

What is claimed is:

1. A process for the production of an elastic composite yarn comprising: crimping a first synthetic multifilament yarn, the filaments of which have a titer greater than about six denier, by temporarily high twisting the yarn, heat setting the yarn while in the twisted state and releasing the twisted yarn; crimping a second synthetic multifilament yarn by temporarily high twisting the yarn, heat setting the yarn while in the twisted state and releasing the twisted yarn; and ply-twisting the first and second yarns to form a composite yarn.

2. The process of claim 1 wherein, prior to ply-twisting with the second yarn, the first yarn is wrapped with staple fibers.

3. The process of claim 1 wherein, prior to ply-twisting, the first and second yarns are each wrapped with staple fibers.

4. The process of claim 1 wherein the composite yarn is additionally ply-twisted with another crimped synthetic multifilament yarn.

5. A yarn comprising a first highly crimped synthetic multifilament yarn component, the individual filaments of which have a titer of at least six denier, ply-twisted with one additional crimped synthetic multifilament yarn component.

6. The yarn of claim 5 wherein the first yarn component has a total titer of from to about 200 denier and the individual filaments have a titer from about 10 to about 20 denier.

7. The yarn of claim 5 wherein the individual filaments of the additional yarn component have a titer of from 2.0 to about 3.5 denier.

8. The y arn as in claim 5 wherein the first yarn component is wrapped with a staple fiber.

9. The yarn as in claim 5 wherein both the first and additional yarn components are each wrapped with a staple fiber.

10. The yarn of claim 5 'wherein the ply-twisted first and additional component are additionally ply-twisted with a third crimped synthetic multifilament yarn component.

References Cited UNITED STATES PATENTS 2,203,721 6/ 1940 Dingley et a1. 57-157 2,777,310 1/1957 Comer 57-157 2,890,567 6/ 1959 Taylor et al. 57-140 2,991,615 7/1961 Stanton 57-144 3,115,745 12/1963 Lathem et al 57-140 XR 3,169,363 2/1965 Martin 57-152 3,220,173 11/1965 Pitzl 57-142 3,306,081 2/1967 Miles et al. 57-152 2,904,952 9/1959 Weiss et al. 57-157 2,936,569 5/1960 Mull 57-157 XR 3,196,602 7/1965 Jenkins et al. 57-157 3,303,640 2/196'7 Reid et a1. 57-163 DONALD E. WATKINS, Primary Examiner.

US. Cl. X.R. 57-144, 157, 

